body,h1,h2,h3,h4,p,ul,ol{
   margin: 0; 
   padding: 0;
}
a{
    color: initial;
    text-decoration: none;
}
/*重置文本框和按钮*/
input,button{
    border: none;
    outline: none;
    outline-offset: 0;
}
/*重置按钮背景*/
button{
    background: initial;
    padding: 0;
}
summary{
    list-style: none;
}

ul,ol{
    list-style: none;
}
input,button{
    border: none;
    outline: none;
    outline-offset: 0;
    margin: 0;
    padding: 0;
}
.left{
    float: left;
}
.right{
    float: right;
}
.clearfix::after{
    content: '';
    clear: both;
    display: block;
}

